DailyDirt: Birds Do The Darndest Things

from the urls-we-dig-up dept

It's fascinating to watch birds, not just because birds can fly, but also because some birds are incredibly intelligent and can perform some pretty cool tricks. If you can step away from playing with Angry Birds for a bit, watch a few of these much calmer bird videos.

Re:

Flocks are locally 2D, globally 3D

If you look at flocks of birds, you’ll notice that each bird only has immediate neighbours in a 2D plane, not completely surrounding them in 3D space. So the flock is effectively like a “sheet” of birds, albeit one that can reorient itself and curl over etc in 3D space.

PS: if it were to come to an intelligence contest between flying birds and cetaceans (whales, dolphins), I’d go with the avians any time.

Re: Re: Flocks are locally 2D, globally 3D

I don't think so. I've seen Discovery/Natgeo and the likes enough to notice that the fiches work in 3D formations.

My bet is that the birds fly in a sheet style formation because of aerodynamics. Think about migratory birds for instance. The birds in the front receive most of the air friction so they need to be fairly rested. It's said they keep switching positions and the leader goes to the back row to rest. Well, it makes sense, in the back row they'll get the "vacuum" and they'll need to spend much less effort flying (think Formula 1, the car behind gets this advantage). Also, if they keep the sheet formation they'll act as one giant wing which will probably lower the overall energy they need to spend flying (this time I'm making an assumption, I'm not sure about that).

Fishes on the other hand have different needs. As far as I know they swim in large schools as a defensive mechanism against predators. When some larger predator attacks they can put the old and sick fishes to the outer defense layer while the younger and fertile ones go in the middle reducing the losses to the 'bad' part. I think it's much more difficult to hunt a solid mass of fishes than a plain "sheet" of fishes. In a 2D formation all you'd have to do as a predator is swim through while the compact 3D build forces the predator to attack the sides and turn, making it less effective (obviously, it depends on the size of the predator).

All of them obviously move in 3D but as a group it makes all difference depending on what the goal is. It would be interesting to see if migratory aquatic animals behave like the birds while migrating from one point to another. While the water density is different, the fluid dynamics might be the same (at different speeds of course).